Respirator



H. 8. COVER Sept. 8, 1935.

RESPIRATOR Filed May 9, 1934 2 Sheets-Sheet l Jimw f 17 21; are

H. 8. COVER Sept. 8, 1936.

RE SPIRATQR 2 Sheets-Sheet 2 Filed May 9, 1954 jkzwrzfar: Ma {y 221);

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stant vigil to enforce his order.

do not deliberately plan to suffer some injury or Patented Sept. s, 1936 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to improvements in respirators and has for an object the provision of such r a device which because of its construction will aflord the user a much higher degree of comfort and will at the same time afford him a high degree of protection against the inhalation of noxious fumes, gases, and foreign particles present in the immediately surrounding atmosphere.

Respirators in general are quite old and many variations in construction and in operation have been made at various times in an attempt to produce a respirator which may be used without creating unsatisfactory conditions for the wearer. In peace time, respirators find their greatest field of utility in industrial plants and undertakings. Because of the dangerous and unhealthy conditions of the atmosphere in such surroundings employers have been forced to provide protecting devices for their workmen in order to escape liability for injuries and ill health suffered and contracted by employees during their course of employment. Every one familiar with the situation is well aware of the fact that even though the most modern and efiicient protecting devices are provided, many workmen will not use them un-' less the employer insists and maintains a con- The workmen contract some illness by disobeying the orders but prefer to take chances rather than undergo the discomfort attendant upon use of the protecting devices furnished. In the use of respirators the main discomforts experienced are obstruction of vision, impeded respiration, moisture of condensation, perspiration, and the forced breathing of preheated air regardless of the temperature of the surroundings. I propose to reduce these discomforts to a minimum and practically eliminate some of them. In so doing I do not impair the emciency of my respirator to any degree whatsoever and believe that by making such improvements much illness, injury, and financial loss will be eliminated because the protection aiforded will be availed of more universally.

In my present invention I- propose to reduce the heat factor by providing'an inwardly opening check valve for governing the intake openings from the filter ,chambers and thus force exhaled air to be expelled through a conveniently located high capacity exhaust valve. By such an arrangement the filter pads or other filter substances will be subjected only to the cooling effect of the air outside the respirator and cannot absorb the heat of the exhaled air because the check valve closes the passageway fromthe interior of the respirator to the filtering material; the user of the respirator will then be able to breathe clean filtered air having a temperature substantially equal to that of the atmosphere and not be subjected to the discomfort of breath-- ing through filtering material which has been heated and contaminated by his own exhalation. I propose to accomplish this object without the sacrifice of clear vision and do so by incorporating into one unit a filter chamber and check 10 further reduces the heat factor to a considerable 15 extent because the exhaled air is expelled very rapidly and easily and is not forced to proceed through a tortuous or obstructed path.

,Another object of my invention is the accomplishment of the above mentioned objects at a very low cost. This object is achieved -.-by employing cheap but effective materials, reduction of the number of parts, and reduction of the number of manufacturing steps.

The invention of this application is broadly related to the inventions described and claimed in my copending applications, Serial Nos. 662,929, 684,503, 684,968, and 722,619, filed respectively on March 2'7, 1933, August 10, 1933, Au ust 14, 1933, and April 27, 1934. v

Other objects will appear hereinafter.

My invention may be best understood by reference to the accompanying drawings, in which:

Fig. 1 is a top plan view;

Fig. 2 is a side elevational view with the filter cap and material removed;

Fig. 3 is a view of the filter cap with parts broken away and illustrating the filter material customarily held in place by the filter cap;

Fig. 4 is a sectional view taken substantially on the line 4-4 of Fig. 2; v

Fig. 5 is a sectional view taken substantially on the line 5--5 of Fig.1;

Fig. 6 is a sectional view taken substantially on the line 6-8 of Fig. 4 and has certain parts broken away;

Fig. 'I is a sectional view taken substantially on the line 'I-l of Fig. 5 and also has parts broken away; and

' Fig. 8 is a detail view of the exhaust valve disc preferably employed for closing the filter chamber from exhaled air.

Referring now to 1, my device comprises generally a respirator body indicated at Ill and comprising preferably a unitary main body portion moulded from flexible and resilient rubber and having side faces II and I2 and upper and lower faces l3. Nose entrance cut-outs H are provided in upper and lower faces I3 and are substantially identical in shape and relative location. As can be seen from Fig. l, the rear end of the device, namely the end in which the cutouts H are located, is of considerably greater breadth and depth than the opposite end and the rear end is likewise open. This permits the entrance of the front portions of the user's face and since the cut-outs H are identical it makes no difference whether one face having one of the cut-outs I4 is arranged to be the "upper face or whether the opposite similar face is so positioned. An attaching strap 5 is anchored to said face H by an anchoring bolt I6 and the buckle |1 carried on the opposite end of strap I5 is adapted to cooperate with the free end of securing strap I8 whose opposite end is anchored to said face l2 by anchoring bolt IS. The end of the respirator opposite the end which has just been described is narrowed to a considerable extent and gives in top plan view the appearance of a wedge formation. Likewise, as can be clearly seen in Fig. 2, a wedge-shaped appearance may be observed by viewing the device in side elevation. Since the upper and lower faces and side faces of the device tend to converge, this visual eflect results. As before stated, the various walls of the device are formed into one integral piece of flexible and resilient rubber material, and these walls are expanded into a bulbous exhaust valve chamber after converging somewhat closely together. Since this portion of the device is immediately in front of the nostrils of the user it provides an extremely well located exhaust valve chamber. Upper and lower exhaust openings 2| and 22 are provided in the bulbous extension 20 and permit the escape of exhaled air from the interior of the device.

Referring now to Figs. 5 and '1, the interior wall of the bulbous extension is thickened at the rear thereof to provide a protruding bead 23 against which the marginal portions 24 of a base plate 25 are adapted to flndsupport; The base plate 25 is provided with a forwardly extending flange 26 which abuts at its forward edge against a pair of spaced retaining lugs 21. The lugs 21 and the bead 23 thus in eflect provide a retaining groove in which the exhaust valve frame constituted by the base plate 25 and flange 26 is securely retained. Since the inner wall of the retaining groove is of smaller dimension than the perimeter of flange 28 the flange is also constrictively retained. An airtight Joint results from this conltruction.

The base plate as is provided with a pair of exhaust apertures 28 through which air may be exhaled. An exhaust valve diaphragm or flap is anchored to base plate 25 by a pair of spaced pins 38 and the diaphragm is of sufficient dimension to cover entirely the spaced exhaust openings 28. Suflicient clearance for free movement of diaphragm 28 is allowed between its marginal edge and the inner wall of flange 26. The diaphragm is secured to the forward face of base plate 25 and thus assumes the position shown in dotted lines in Fig. 5 when exhalation occurs. The openings 28 are in vertical alignment preferably with the exhaust openings 2| and 22 and thus permit free and direct exit from the interior of the respirator.

Referring now to Fig. 4, laterally extending annular flanges 3| and 32 are provided on side faces II and I2 respectively, and filter openings 33 and 34 are arranged in circular formation within annular flanges 3| and 32 respectively and one of said openings is arranged centrally of the circular formation within each of said flanges. Attaching bosses or lugs 35 and 36 are arranged to extend laterally from the outer walls of flanges 3| and 32 respectively at points substantially ninety degrees removed from each other on said flanges. These attaching lugs 35 and 36 just described are employed for anchoring a perforated valve carrying filter chamber base wall which will be presently described.

The filter chamber wall just described is shown in section in Fig. 4 and in elevation in part in Fig. 2. Referring now to Fig. 4, this member comprises a perforated cap 31 having openings or enlarged perforations 38 in the top wall thereof and arranged in a circular formation. Openings or slots 39 are provided in said walls of the cap 31 and arranged to'cooperate with attaching lugs 35 and 36 of flanges 3| and 32. A laterally extending flange 40 extends entirely around theperiphery of the base of cap 31 and is in turn embraced in the fold 4| formed at the base of a threaded ring 42 which is preferably arranged concentrically to the cap 31. In section the fold 4| presents a U-shaped formation opening inwardly toward the center of the ring 42 and is provided by expanding the base of the ring 42 outwardly and laterally of its wall and then bending the extended portion inwardly and over the flange 40 of the cap 31. At the top of the side wall of ring 42 an inwardly extending annular flange 43 is provided and serves as a support for the marginal portions of filter material 44. Since the depth of ring 42 is greater than that of cap 31 and since the ring 42 is likewise greater in cross-sectional dimension, an air space of considerable volume is provided between the exterior of cap 31 and the interior of ring 42 and filter material 44. A filter retaining cap having an inwardly extending flange 46 retains filter screen 41 against the outer surface of filter material 44 and when the cap 45 is screwed onto ring 42 the filter material is clamped at its marginal portions between the interior of flange 46 and the exterior of flange 43.

The upper-end of cap 31 is preferably provided at its center with an opening through which a -bolt 48 is extended. An enlarged head 49 is provided on the inner end of bolt 48 and is undercut to provide a shaft of smaller cross-sectional dimension than the head 49. The main shaft of the bolt is of smaller cross-sectional dimension than the undercut portion of head 49 and thus provides a retaining shaft between head 49 and the top of cap 31. An exhaust valve disc or diaphragm 50 is preferably circular in formation and provided at its center with an annular opening 5| of smaller dimension than the cross-sectional dimension of head 49 but of slightly larger dimension than the cross-sectional dimension of the undercut portion of head 49. 'Thus the diaphragm 50. may-revolve freely around the axis of thebolt 48 and is permitted a slight degree of axial movement on said bolt. The end of bolt 48 opposite the head 49 is threaded to cooperate with the internal threads of a thick annular spacing nut 52. The outer end of nut 52 presses against the inner face of filter material 44 at its center and thus spaces the filter material from the outer face of cap 31. A free air passage and chamber are consequently maintained and air may pass freely through the filter screen 41, filter aoaasee device is understood but a short description will be given. The entire filter chambers on either side of the main body portion l may be aflixed to the flanges 3i and 32 by compressing said flanges slightly and lining up the attaching lugs 35 and 35 so as to enter the slots 39 of the cap 3?. When this is done the resilience of the rubber material of which the flanges are made causes the lugs to be forced forwardly and into-said slots. The filter material It is arranged in proper position on flange 63 and the retaining cap 45 holds it tightly clamped against said flange 43. The spacing nut 52 prevents the center of the material from sagging inwardly to come into contact with the perforated outer face of cap 31. As the user inhales, the portions of diaphragm 50 which are removed from its center move away from the inner face of perforated wall of cap 31 and permit air to be drawn through the filtering material and into position to be inhaled by the user. During this period of time the diaphragm 29 of the exhaust valve is brought into close contact with the base plate 25 and thus covers the apertures 28 in said plate. As soon as exhalation starts, the diaphragm 50 moves to a closed position and the diaphragm 29 moves to an open position indicated in dotted lines in Fig. 5.

,The replacement of filter material 44 may be accomplished by unscrewing retaining cap 45 from the ring 42 in order to free the filter material from the clamping engagement, an unused filter pad may be substituted, and cap 45 replaced. The diaphragm 50 may be replaced by a new one by simply pulling it away from its engagement by the head 49 of bolt 48. The exhaust valve may be removed for replacing or cleaning its diaphragm by deforming the wall of bulbous extension 21 in order to free the flange 26 from the gripping engagement of the bead 23 and lugs 27. The exhaust valve may then be withdrawn from the rear of the respirator.

From the foregoing description, when taken in connection with the drawings, it can be seen that the filtering material 44 is protected from exhaled air and that the structure employed for this purpose does not consume any additional space. If it is desired to employ an additional layer of filter material it may be held in place in the same manner by cap 65 and the only difference would be. that the cap would not be screwed down so far on ring d2.

While I have illustrated and described the preferred form of construction for carrying my in-' vention into efiect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent 'is: 4

1. In a device of the character described, a

filter chamber having a perforated base wall, a

check valve diaphragm secured to said base wall in position so as to close the perforations of said base wall when pressure is exerted on said diaphragm in one direction, filtering material arranged on the opposite side of said base wall, an externally screw threaded ring arranged concentrically of said base wall and secured thereto, an internally threaded cap member having an inwardly extending flange adapted to clamp said filtering material between said flange and said externally screw threaded ring.

2. In a device of the character described, a filter chamber having a perforated base wall, a check valve diaphragm secured to said base wall in position so as to close the perforations of said base wall when pressure is exerted on said diaphragm in one direction, filtering material arranged on the opposite side of said base wall, an externally screw threaded ring arranged concentrically of said base wall and secured thereto, an internally threaded cap member having an inwardly extending flange, a filtering screen internally of said cap member and covering said filtering material, said internally extending flange of said cap member being adapted to clamp the marginal portion of said screen, and said filtering material against said externally screw threaded ring when said cap is screwed on to said ring.

3. A device as set forth in claim 1 further characterized by a spacing member arranged between the perforated base wall and the filtering material, substantially as described.

' 4. A device as set forth in claim 1 in which the clamping means for the edge of the filter normally spaces the filtering material from the perforated base wall, and a spacing member arranged between the centers of said filtering materials and said base wall, substantially as described.

HARVEY S. COVER. 

